[Miros1]

1) Back up your existing hood, just in case.
2) Open up your My Documents/EA Games/The Sims 2/Neighborhoods folder.
3) Use the right mouse button to drag the desired hood to an empty spot in the folder. Choose "Copy" from the context menu that pops up when you remove your finger from the mouse button.
4) Rename the hood folder to N00#, where # is an unused hood number.
Note: If you use a number higher than 10, keep the number of digits the same! Neighborhood 99 would now be N099.
5) Double click the renamed folder.
6) Press control-F (for the Windows search function). Search for N00*, where * is the old 'hood number.
7) Patiently (and tediously) rename each file and folder to the new hood number.
8) Open SimPE and change to "plug in" mode (tabs at the bottom) if necessary.
9) Open the Neighborhood Browser under the Edit menu.
10) (I think, I'll have to check) The neighborhood ID should come up on the first page displayed in the bottom window.
11) Click the link for "Make Unique." This should change the GUID for the whole hood to an unused one.